As lovely as 3D printing an object, snapping it off its build plate, and immediately using it may sound, the reality is that just isn’t the case. Once the printer has done its job, you often need to do a few things to call your printed object a success.
There are many different methods to post-process your 3D-printed objects, so this makeshift guide will cover just the basics and a few tips and methods that we use at NAG HQ. If you think you have better tips for us to follow, comment them down below, and we’ll see if they fit our flow better than we already know. *heart hand emoji*
Generally, we do the following steps once our printer has done its job:
1. Remove the print from the build plate
2. Handle the printed supports
3. Clean up the printed object
4. Paint!
First, let’s tackle filament printing, as this is more than likely the most common 3D printing you’ll come across.
The filament printer lays down lines of hot, gooey plastic repeatedly until the object is built. It sounds simple enough, and it is. The post-printing process for filament printers can be relatively simple, but there are some instances where getting your object paint-ready might be a little tricky.
We recommend wearing a pair of builders gloves for this process as you’ll be dealing with knives and sometimes the supports like to fight back.
Step 1: Remove the print from the build plate. With a filament printer, this is relatively simple. You just hold on tightly to the print and twist it off. If it doesn’t come off easily, a little wiggling back and forth helps, but we don’t want to be too aggressive here as we don’t want to snap the object. The print usually comes off in one go, and you’re done.
If you find yourself struggling to remove your prints, you can look for a more flexible build plate to go in your printer. The Build Plate A, that comes with the Crealtiy K1 series has a bit of flex to it that allows you to ever so slightly pop the print off if it doesn’t want to let go.
If you’re lucky enough to be printing an object that doesn’t require any supports you can skip straight to step 3 of the post-printing process. Otherwise, read along with us, and you should find yourself on the other side with a nice, neat little widget.
Step 2: Handle the printed supports. Removing supports from a filament print is probably one of the least favourite things around the office. If we can, we’ll palm the task off to some random who just walked into the office at the wrong time.
Pulling, cutting and breaking the supports off are pretty much the basic skills used here, but sometimes they can be a little scary, so here’s what we try and do to bolster our confidence and make removing the supports easier.
If we just can’t go without supports, we’ll dial in our support settings as best as possible to make them easier to remove. First, make sure your support Top Z Distance or Top Contact is at least double your layer height. This ensures a slight gap between the supports and the object, which makes it a little easier to pull off. Second, add an interface layer or two. This prints a layer in a different pattern to your object between the support and the object, making removing it easier.
A pair of small side cutters and a long nose plier also go a long way to helping you remove the supports from the object before cleaning it up.
In most cases, “Tree” type supports are easier to remove, but they can get a little thick sometimes and may not always cover where they are needed, so be sure to double-check them. Some people go as far as printing the supports in a different material, but to do that, you’ll need a bit of a sophisticated printer with dual printing nozzles.
If you are still struggling to remove the supports, you can always use a hair dryer to heat them up, making them more malleable and easier to pull off with a pair of long nose pliers.
Step 3: Clean up the printed object. Now that we finally have an object with no supports hanging on, we can clean it up and make sure there are no pokey bits or strings we don’t want to see. For this step, a pair of builders gloves comes in handy as we’ll be using a small knife to remove some of the bits.
Make sure you point the knife away from you whenever you remove the trailing bits of supports or a leftover string.
Once you’ve done the grunt work with the knife, it’s time to move on to sanding. For objects with big open spaces, like a mask, you’re going to be doing as much sanding as possible to try and eliminate those layer lines. With more detailed figures, you may get away with a little less sanding, but if you want a clean, smooth finish, unfortunately, you’ll have to sand. A lot. A good grit to start on is 120 grit, then move up to 220, and finish off at 320. This all depends on how smooth you want the object. Of course, you could be extremely lazy and just leave it as is. It’s your object, after all.
You can get a little cheeky, which we do, and use Filler Primer from Rustoleum to help with the process. A coat of this fills in a few of the layer lines, making the object seem smoother than it really is. We still need to sand the primer once it’s gone down, as it can be a bit gritty, but after two or three coats and sanding, the end product is what we would call pretty decent.
4. Paint! By this stage we should have a pretty smooth object ready for some paint. We have already primed it in the previous step, so we shouldn’t need to give it another coat. If you have given it a good sanding, one last coat of regular primer should do the trick.
Now, we can spray paint, brush paint, or finger paint the object however we like. We generally stick to the Rustoleum brand for rattle-can paintings, and we’re quite fond of Vallejo paints for figures and airbrushing. These just seem to cover the best and have a good, long-lasting finish.
If you’ll be handling your object quite a bit, a nice coat of Clear Coat should provide extra protection.
It’s worth noting that you’ll probably have quite a lot of scrap plastic lying about once you’re done with removing all the supports and other scrappy bits. In general, these bits are not recyclable, so don’t toss them in the recycling bin. You can look at grinding them down and using them in heat moulds, but you’ll probably toss them away, so keep a bin close.
After all that, just make sure your build plate is clear of any leftover filament, pop it back into your printer, and you’re good for the next print.
“A relatively simple process that sometimes requires more time than I really want to spend to get the perfect object” is generally how we’d describe the post-processing of filament printing. So, be sure to have your settings dialled in as best as possible to avoid spending more time than you’d like to finish the object.
The post-printing process for Resin can be much, much quicker, but it’s also much, much messier. The best part about it, though, is that you kind of feel like a chemical engineer. What’s not fun about that?
Before you do anything with resin printing, please ensure you are gloved up in some good ol’ nitrile gloves. If you are sensitive to the smell, we recommend a face mask as well.
You’ll also need some sort of solvent (we suggest IPA, or Iso-propyl Alcohol, 90% and up), a separate resin-printing-dedicated bucket, and a lot of paper towels. Like, a lot, a lot. In fact, go to your nearest bulk store and buy one of those giant rolls restaurants use to dry your hands. Trust us, it’s worth it.
Resin prints also need to be cured by UV light, and there are many ways to do this. The most affordable way is to stick them in the sun for a good few hours, but that takes… well, a good few hours. You can purchase a UV torch that you can shine on your prints by hand, or you can pick up a curing station from your local 3D store to help with the process. A dual washing and curing station is worth the investment if you’re doing a lot of printing. It’s also just a heck of a lot more convenient than waiting on the sun.
The four steps we follow are the same, but the way we go about doing them is completely different, so pay attention.
Step 1: Remove the print from the build plate. First, you’ll want to let the liquid resin still on the build plate run off back into the vat. Once you’ve unscrewed the plate, just tilt it a little to allow gravity to do its job. Once you’re happy with what’s left on the build plate, place it on a bundle of paper towels, so you don’t mess the resin on your table. Using the scraper you got with your printer, just wedge the thin part underneath your print to pop it off the build plate, being careful not to scratch the plate (which will inevitably happen). Now pop your printed object, supports and all, and your build plate into a bucket of hot water.
The hot water will soften up the supports just enough to make them easy to snap right off, and popping the build plate in there just makes it easier to wipe off all the excess resin, which you can do while your prints soften up.
After about five or so minutes, and with your build plate clean, it’s time to move on to step two.
Step 2: Handle the printed supports. Generally, resin supports are very easy to remove, especially if they’ve been soaking in hot water for a few minutes. You just pull them right off, ensuring you aren’t accidentally removing a sword from your miniature, and that’s pretty much it. You can also use your knife to cut off any bits that shouldn’t be on the print, as the resin is still soft enough to work with.
Step 3: Clean up the printed object. Once you’ve removed all the supports from your print, it’s time to clean and cure them. The first step is to either pop them in your washing station with the aforementioned IPA or in a bucket, again with the IPA. The wash station will do everything for you, but if you’re doing it by hand, just muddle the prints around in the IPA, removing any excess resin from all the nooks and crannies. Do this for around two to three minutes.
Then dry them up with some paper towel and make sure there’s no liquid still left on the print.
Now, you pop the machine into curing mode and let it cure for 30-45 seconds, depending on the object’s size. When it’s done, you don’t want it to feel soft and sticky. It should feel hard, like a plastic toy. If you’re using the UV torch, you may want to do this for a bit longer, say five or so minutes, ensuring you cover all the hidden bits. If you’re doing it with the sun, well, just pop it outside and make sure to rotate and check on it every fifteen or so minutes. You’ll need to do this for at least three hours if it’s small, but it could take the whole day if necessary.
The entire time, just keep cleaning up your spills with that paper towel, being sure not to throw any of it in your regular dustbin.
Once your object is cured, it’s ready for painting!
4. Paint! Finally, your cured print is ready to take on some primer and then a lovely dose of colour. Because we aren’t filling any gaps with the resin print, we like to use the standard Rustoleum Primer, without Paint, to prime the prints. Once you’ve got a good coat of primer on, the object is ready for its glow-up.
Again, we recommend Rustoleum for rattle cans and Vallejo for air and paint brushing. Then finish off your paint with a nice clear coat in either matte or gloss for that extra protection.
An important thing to remember here is that resin is poisonous, so you should try your best not to touch it. Even an uncured print can irritate your skin. This is also why you should not throw any of the supports or cleaning towels away in your regular dustbin.
Best practices would have you cure the supports and paper towel in your curing station or in the sun before being thrown away.
There you have it: the ugly side of 3D printing that you never see on Instagram, all simplified and wrapped up in a neat, 3D-printed bow just for you to digest. As always, you can contact us if you have any questions at [email protected]. Otherwise, talk to the professionals at 3D Store, for all your product and accessory enquiries.
Happy printing hobbyists!
